Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area o... more Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area of land, can potentially improve the environmental performance of agricultural systems in Europe. However, such changes in land use also need to be seen in terms of their economic implications. The present study makes a combined environmental and economic assessment of poplar SAF near Torrijos in Castilla la Mancha in Spain. Six different silvoarable systems were compared with existing arable agriculture. The Revised Universal Soil Loss Equation (RUSLE) was used to predict soil erosion under the different silvoarable and arable systems and an economic model was used to predict their NPV. SAF with contouring decreased predicted soil loss by 80% compared with the existing arable system. Economic analysis showed that the NPV of densely planted, but widely spaced silvoarable systems could be similar to the NPV of existing arable systems. However, current grant schemes were higher for the arable systems and made the silvoarable systems less attractive in terms of cash flow and NPV. It is concluded that where soil erosion is problematic, grant systems should not increase the attractiveness of arable systems at the expense of SAF.
Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area o... more Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area of land, can potentially improve the environmental performance of agricultural systems in Europe. However, such changes in land use also need to be seen in terms of their economic implications. The present study makes a combined environmental and economic assessment of poplar SAF near Torrijos in Castilla la Mancha in Spain. Six different silvoarable systems were compared with existing arable agriculture. The Revised Universal Soil Loss Equation (RUSLE) was used to predict soil erosion under the different silvoarable and arable systems and an economic model was used to predict their NPV. SAF with contouring decreased predicted soil loss by 80% compared with the existing arable system. Economic analysis showed that the NPV of densely planted, but widely spaced silvoarable systems could be similar to the NPV of existing arable systems. However, current grant schemes were higher for the arable systems and made the silvoarable systems less attractive in terms of cash flow and NPV. It is concluded that where soil erosion is problematic, grant systems should not increase the attractiveness of arable systems at the expense of SAF.
Natural disturbances play a key role in ecosystem dynamics and are important factors for sustaina... more Natural disturbances play a key role in ecosystem dynamics and are important factors for sustainable forest ecosystem management. Quantitative models are frequently employed to tackle the complexities associated with disturbance processes. Here we review the wide variety of approaches to modelling natural disturbances in forest ecosystems, addressing the full spectrum of disturbance modelling from single events to integrated disturbance regimes. We applied a general, process-based framework founded in disturbance ecology to analyze modelling approaches for drought, wind, forest fires, insect pests and ungulate browsing. Modelling approaches were reviewed by disturbance agent and mechanism, and a set of general disturbance modelling concepts was deduced. We found that although the number of disturbance modelling approaches emerging over the last 15 years has increased strongly, statistical concepts for descriptive modelling are still largely prevalent over mechanistic concepts for explanatory and predictive applications. Yet, considering the increasing importance of disturbances for forest dynamics and ecosystem stewardship under anthropogenic climate change, the latter concepts are crucial tool for understanding and coping with change in forest ecosystems. Current challenges for disturbance modelling in forest ecosystems are thus (i) to overcome remaining limits in process understanding, (ii) to further a mechanistic foundation in disturbance modelling, (iii) to integrate multiple disturbance processes in dynamic ecosystem models for decision support in forest management, and (iv) to bring together scaling capabilities across several levels of organization with a representation of system complexity that captures the emergent behaviour of disturbance regimes.
Large efforts have been dedicated to investigate effects of acid atmospheric deposition on trees ... more Large efforts have been dedicated to investigate effects of acid atmospheric deposition on trees and soil at the forest stand level. For this purpose intensive monitoring programs and integrated simulation models were developed. This paper describes the application of the models NuCSAM, SoilVeg and ForGro to the Speuld site, a Douglas fir stand on a podzolic soil. The site was monitored between 1987 and 1992. Atmospheric inputs and element outputs at Speuld are fairly representative for Dutch forests. The models were parameterized and calibrated for this site. Simulated soil water contents, soil solution chemistry, foliage biomass and nutrient status and stem growth between 1987 and 1992 were comparable with observations. The generality of the SoilVeg and ForGro model was further tested by an approximate simulation of a site irrigation and fertigation experiment at a nearby Douglas fir site between 1987 and 1991. The direction and magnitude of simulated effects of irrigation and fertigation on stem growth, litter fall and needle nutrient status were generally right, but the observed enhanced N-mineralization could not be simulated. Simulations of site response to the Dutch target deposition scenario between 1994 and 2050 showed large differences between the three models, particularly for nitrogen cycling and foliage nutrient status. Nonetheless all models indicate a fast response of soil solution chemistry to changing deposition. Both SoilVeg and ForGro indicate that direct effects of air pollution and effects of soil pH and A1 are subsidiary to effects of drought and nitrogen. Our understanding of effects of acid atmospheric deposition on forests, based on lab trials, relatively short site monitoring studies and integrated simulation models, is still inadequate to quantitatively predict the long-term impact of acid deposition on forests on a nationwide scale.
In the Iberian Peninsula Mediterranean oak forests have been transformed into a mosaic landscape ... more In the Iberian Peninsula Mediterranean oak forests have been transformed into a mosaic landscape of four main patch-types: forests, savannas, shrublands and grasslands. We used aerial photographs over a period of 45 years to quantify the persistence and rates of transitions between vegetation patch-types in southern Portugal, where cork oak is the dominant tree species. We used logistic regression to relate vegetation changes with topographical features and wildfire history. Over the 45 years, shrublands have been the most persistent patch-type (59%), and have been expanding; forests are also persistent (55%) but have been decreasing since 1985; savannas and grasslands were less persistent (33% and 15%, respectively). Shrublands persistence was significantly correlated with wildfire occurrence, particularly on southern exposures after 1995. In contrast, forest persistence decreased with wildfire occurrence, and forests were more likely to change into shrublands where wildfire had occurred after 1995.
ABSTRACT There is increasing awareness that natural and anthropogenic disturbance in forests affe... more ABSTRACT There is increasing awareness that natural and anthropogenic disturbance in forests affects exchange of CO2, H2O and energy between the ecosystem and the atmosphere. Consequently quantification of land use and disturbance intensity is one of the next steps needed to improve our understanding of the carbon cycle, its interactions with the atmosphere and its main drivers at local as well as at global level. The conventional NPP-based approaches to quantify the intensity of land management are limited because they lack a sound ecological basis. Here we apply a new way of characterising the degree of management and disturbance in forests using the self- thinning theory and observations of diameter at breast height and stand density. We used plot level information on dominant tree species, diameter at breast height, stand density and soil type from the French national forest inventory from 2005 to 2010. Stand density and diameter at breast height were used to parameterize the intercept of the self-thinning relationship and combined with theoretical slope to obtain an upper boundary for stand productivity given its density. Subsequently, we tested the sensitivity of the self-thinning relationship for tree species, soil type, climate and other environmental characteristics. We could find statistical differences in the self-thinning relationship between species and soil types, mainly due to the large uncertainty of the parameter estimates. Deviation from the theoretical self-thinning line defined as DBH=αN-3/4, was used as a proxy for disturbances, allowing to make spatially explicit maps of forest disturbance over France. The same framework was used to quantify the density-DBH trajectory of even-aged stand management of beech and oak over France. These trajectories will be used as a driver of forest management in the land surface model ORCHIDEE.
The paper describes the Version 2 of the CO2FIX (CO2FIX V.2) model, a user-friendly tool for dyna... more The paper describes the Version 2 of the CO2FIX (CO2FIX V.2) model, a user-friendly tool for dynamically estimating the carbon sequestration potential of forest management, agroforesty and afforestation projects. CO2FIX V.2 is a multi-cohort ecosystem-level model based on carbon accounting of forest stands, including forest biomass, soils and products. Carbon stored in living biomass is estimated with a forest cohort model that allows for competition, natural mortality, logging, and mortality due to logging damage. Soil carbon is modeled using five stock pools, three for litter and two for humus. The dynamics of carbon stored in wood products is simulated with a set of pools for short-, medium-and long-lived products, and includes processing efficiency, re-use of by-products, recycling, and disposal forms. The CO2FIX V.2 model estimates total carbon balance of alternative management regimes in both even and uneven-aged forests, and thus has a wide applicability for both temperate and tropical conditions. Results for the model testing and validation in selected temperate and tropical forest management systems are presented and discussed.
... Conservation and development trade-offs; Globalized trade and investment; Production forests.... more ... Conservation and development trade-offs; Globalized trade and investment; Production forests. Search; Order; Resource centre: Quick guide to our services. ... Authors: Masera, OR; Garza-Caligaris, JF; Kanninen, M.; Karjalainen, T.; Liski, J.; Nabuurs, GJ; Pussinen, A.; de Jong, BHJ ...
Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area o... more Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area of land, can potentially improve the environmental performance of agricultural systems in Europe. However, such changes in land use also need to be seen in terms of their economic implications. The present study makes a combined environmental and economic assessment of poplar SAF near Torrijos in Castilla la Mancha in Spain. Six different silvoarable systems were compared with existing arable agriculture. The Revised Universal Soil Loss Equation (RUSLE) was used to predict soil erosion under the different silvoarable and arable systems and an economic model was used to predict their NPV. SAF with contouring decreased predicted soil loss by 80% compared with the existing arable system. Economic analysis showed that the NPV of densely planted, but widely spaced silvoarable systems could be similar to the NPV of existing arable systems. However, current grant schemes were higher for the arable systems and made the silvoarable systems less attractive in terms of cash flow and NPV. It is concluded that where soil erosion is problematic, grant systems should not increase the attractiveness of arable systems at the expense of SAF.
Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area o... more Silvoarable Agroforestry (SAF), the deliberate combined use of trees and crops on the same area of land, can potentially improve the environmental performance of agricultural systems in Europe. However, such changes in land use also need to be seen in terms of their economic implications. The present study makes a combined environmental and economic assessment of poplar SAF near Torrijos in Castilla la Mancha in Spain. Six different silvoarable systems were compared with existing arable agriculture. The Revised Universal Soil Loss Equation (RUSLE) was used to predict soil erosion under the different silvoarable and arable systems and an economic model was used to predict their NPV. SAF with contouring decreased predicted soil loss by 80% compared with the existing arable system. Economic analysis showed that the NPV of densely planted, but widely spaced silvoarable systems could be similar to the NPV of existing arable systems. However, current grant schemes were higher for the arable systems and made the silvoarable systems less attractive in terms of cash flow and NPV. It is concluded that where soil erosion is problematic, grant systems should not increase the attractiveness of arable systems at the expense of SAF.
Natural disturbances play a key role in ecosystem dynamics and are important factors for sustaina... more Natural disturbances play a key role in ecosystem dynamics and are important factors for sustainable forest ecosystem management. Quantitative models are frequently employed to tackle the complexities associated with disturbance processes. Here we review the wide variety of approaches to modelling natural disturbances in forest ecosystems, addressing the full spectrum of disturbance modelling from single events to integrated disturbance regimes. We applied a general, process-based framework founded in disturbance ecology to analyze modelling approaches for drought, wind, forest fires, insect pests and ungulate browsing. Modelling approaches were reviewed by disturbance agent and mechanism, and a set of general disturbance modelling concepts was deduced. We found that although the number of disturbance modelling approaches emerging over the last 15 years has increased strongly, statistical concepts for descriptive modelling are still largely prevalent over mechanistic concepts for explanatory and predictive applications. Yet, considering the increasing importance of disturbances for forest dynamics and ecosystem stewardship under anthropogenic climate change, the latter concepts are crucial tool for understanding and coping with change in forest ecosystems. Current challenges for disturbance modelling in forest ecosystems are thus (i) to overcome remaining limits in process understanding, (ii) to further a mechanistic foundation in disturbance modelling, (iii) to integrate multiple disturbance processes in dynamic ecosystem models for decision support in forest management, and (iv) to bring together scaling capabilities across several levels of organization with a representation of system complexity that captures the emergent behaviour of disturbance regimes.
Large efforts have been dedicated to investigate effects of acid atmospheric deposition on trees ... more Large efforts have been dedicated to investigate effects of acid atmospheric deposition on trees and soil at the forest stand level. For this purpose intensive monitoring programs and integrated simulation models were developed. This paper describes the application of the models NuCSAM, SoilVeg and ForGro to the Speuld site, a Douglas fir stand on a podzolic soil. The site was monitored between 1987 and 1992. Atmospheric inputs and element outputs at Speuld are fairly representative for Dutch forests. The models were parameterized and calibrated for this site. Simulated soil water contents, soil solution chemistry, foliage biomass and nutrient status and stem growth between 1987 and 1992 were comparable with observations. The generality of the SoilVeg and ForGro model was further tested by an approximate simulation of a site irrigation and fertigation experiment at a nearby Douglas fir site between 1987 and 1991. The direction and magnitude of simulated effects of irrigation and fertigation on stem growth, litter fall and needle nutrient status were generally right, but the observed enhanced N-mineralization could not be simulated. Simulations of site response to the Dutch target deposition scenario between 1994 and 2050 showed large differences between the three models, particularly for nitrogen cycling and foliage nutrient status. Nonetheless all models indicate a fast response of soil solution chemistry to changing deposition. Both SoilVeg and ForGro indicate that direct effects of air pollution and effects of soil pH and A1 are subsidiary to effects of drought and nitrogen. Our understanding of effects of acid atmospheric deposition on forests, based on lab trials, relatively short site monitoring studies and integrated simulation models, is still inadequate to quantitatively predict the long-term impact of acid deposition on forests on a nationwide scale.
In the Iberian Peninsula Mediterranean oak forests have been transformed into a mosaic landscape ... more In the Iberian Peninsula Mediterranean oak forests have been transformed into a mosaic landscape of four main patch-types: forests, savannas, shrublands and grasslands. We used aerial photographs over a period of 45 years to quantify the persistence and rates of transitions between vegetation patch-types in southern Portugal, where cork oak is the dominant tree species. We used logistic regression to relate vegetation changes with topographical features and wildfire history. Over the 45 years, shrublands have been the most persistent patch-type (59%), and have been expanding; forests are also persistent (55%) but have been decreasing since 1985; savannas and grasslands were less persistent (33% and 15%, respectively). Shrublands persistence was significantly correlated with wildfire occurrence, particularly on southern exposures after 1995. In contrast, forest persistence decreased with wildfire occurrence, and forests were more likely to change into shrublands where wildfire had occurred after 1995.
ABSTRACT There is increasing awareness that natural and anthropogenic disturbance in forests affe... more ABSTRACT There is increasing awareness that natural and anthropogenic disturbance in forests affects exchange of CO2, H2O and energy between the ecosystem and the atmosphere. Consequently quantification of land use and disturbance intensity is one of the next steps needed to improve our understanding of the carbon cycle, its interactions with the atmosphere and its main drivers at local as well as at global level. The conventional NPP-based approaches to quantify the intensity of land management are limited because they lack a sound ecological basis. Here we apply a new way of characterising the degree of management and disturbance in forests using the self- thinning theory and observations of diameter at breast height and stand density. We used plot level information on dominant tree species, diameter at breast height, stand density and soil type from the French national forest inventory from 2005 to 2010. Stand density and diameter at breast height were used to parameterize the intercept of the self-thinning relationship and combined with theoretical slope to obtain an upper boundary for stand productivity given its density. Subsequently, we tested the sensitivity of the self-thinning relationship for tree species, soil type, climate and other environmental characteristics. We could find statistical differences in the self-thinning relationship between species and soil types, mainly due to the large uncertainty of the parameter estimates. Deviation from the theoretical self-thinning line defined as DBH=αN-3/4, was used as a proxy for disturbances, allowing to make spatially explicit maps of forest disturbance over France. The same framework was used to quantify the density-DBH trajectory of even-aged stand management of beech and oak over France. These trajectories will be used as a driver of forest management in the land surface model ORCHIDEE.
The paper describes the Version 2 of the CO2FIX (CO2FIX V.2) model, a user-friendly tool for dyna... more The paper describes the Version 2 of the CO2FIX (CO2FIX V.2) model, a user-friendly tool for dynamically estimating the carbon sequestration potential of forest management, agroforesty and afforestation projects. CO2FIX V.2 is a multi-cohort ecosystem-level model based on carbon accounting of forest stands, including forest biomass, soils and products. Carbon stored in living biomass is estimated with a forest cohort model that allows for competition, natural mortality, logging, and mortality due to logging damage. Soil carbon is modeled using five stock pools, three for litter and two for humus. The dynamics of carbon stored in wood products is simulated with a set of pools for short-, medium-and long-lived products, and includes processing efficiency, re-use of by-products, recycling, and disposal forms. The CO2FIX V.2 model estimates total carbon balance of alternative management regimes in both even and uneven-aged forests, and thus has a wide applicability for both temperate and tropical conditions. Results for the model testing and validation in selected temperate and tropical forest management systems are presented and discussed.
... Conservation and development trade-offs; Globalized trade and investment; Production forests.... more ... Conservation and development trade-offs; Globalized trade and investment; Production forests. Search; Order; Resource centre: Quick guide to our services. ... Authors: Masera, OR; Garza-Caligaris, JF; Kanninen, M.; Karjalainen, T.; Liski, J.; Nabuurs, GJ; Pussinen, A.; de Jong, BHJ ...
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